Data input device

ABSTRACT

A data input device comprises a single cathode ray tube whose screen is divided into a plurality of zones. Each zone is scanned with a pattern characteristic of a corresponding code by means of a code matrix. Each pattern excites a zone of the screen to display a corresponding alphanumeric or other symbol with an intensity sufficient to excite a photodetector, which provides an output signal indicative of the code corresponding to a zone when this zone is at least partially obscurated, for increasing the luminous intensity of the character on the screen.

United States Patent Perotto 51 Dec. 26, 1972 [54] DATA INPUT DEVICE[72] Inventor: Pier Giorgio Perotto, Torino, Italy [73] Assignee: Ing.C. Olivetti 8: C.,S.p.A., 1vria(Torino), Italy 221 Filed: Jan. 19, 197121 Appl. No.: 107,718

30 Foreign Application Priority Data Jan. 21, 1970 Italy ..67l58 A/70[52] US. Cl. ..340/365 P, 178/17 C, 178/17 D, 178/18, 235/151, 250/217CR, 340/324 AD [51] Int. Cl. ..G08b 5/36 [58] Field of Search ..340/337,365 P, 165, 365 L, 340/324 AD; 250/217 CR; 178/17 A, 17 C,

[56] References Cited UNITED STATES PATENTS 3,441,722 4/1969 Gloess..235/151 3,114,283 12/1963 Gruner ..250/217 CR X 3,482,241 12/1969Johnson 3,581,003 5/1971 Leone etal ..178/l7D Primary Examiner-David L.Trafton Attorney--Birch, Swindler, McKie & Beckett [5 7] ABSTRACT A datainput device comprises a single cathode ray tube whose screen is dividedinto a plurality of zones. Each zone is scanned with apatterncharacteristic of a corresponding code by means of a code matrix.Each pattern excites a zone of the screen to display a correspondingalphanumeric or other symbol with an intensity sufficient to excite aphotodetector, which provides an output signal indicative of the codecorresponding to a zone when this zone is at least partially obscurated,for increasing the luminous intensity of the character on the screen.

10 Claims, 7 Drawing Figures PATENTEDnmzs I972 31017.15

' sum 1 OF 2 INVENIO PIER GIORGIO PER%TTO BY 31m, MDLER, MCKIE Q BECKTTORNEYS PATENTEDBEL'ZSIWZ SHEET 2 0F 2 c1 me an czs c101 c107 Fig-7mvwrcm PIER GIORGK) PEROTTU DATA INPUT DEVICE BACKGROUND OF THEINVENTION 1. Field of the Invention The present invention relates to adata input device for example forterminal units of data transmission,comprising a cathode ray tube for displaying on the screen thecharacters set up by the operator.

2. Description of the Prior Art Known data input devices are ofmechanical construction and therefore they are limited in flexibilityand speed by the same technology.

, Other known data input devices are costly and complicated, wherebythey are rather expensive.

It is also known another data input device, which is provided with acathode ray tube display controlled by a mechanical keyboard.

SUMMARY OF THE INVENTION 'input device comprising a single cathode raytube whose screen is divided into a plurality of zones, first means forscanning each zone with a pattern characteristic of a correspondingcode, and second means so responsive to light emanating from the zonesas to provide an output signal indicative of the code corresponding to azone when that zone is at least partially obscured.

The cathode ray tube in the device according to the invention can haveits screen divided into a first part for the display of symbols and asecond part comprising the said zones. Data entered by means of thesecond part of the screen can be displayed on the firstpart.

The invention will be described in more detail, by way of example, withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a data inputdevice embodying the invention;

FIG. 2 shows a first example of a section of the screen at an inputzone;

FIG. 3 shows a second example of a section of the screen at an inputzone;

FIG. 4 is a diagrammatic view of the input zones;

FIG. 5 is a diagram of the scanning pattern for some of the zones of theinput device;

FIG. 6 is a block diagram of the data input device.

FIG. 7 is a general block diagram of the input, processing and visualdisplay arrangement.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a cathoderay tube 1 has a screen 2 divided into two parts. The upper part isadapted to provide a visual display of a message; the lower part isadapted to act as a data input device, which, in this example is akeyboard. The part adapted to represent the keyboard is obtained byforming apertures 3, in correspondence with each key, in a layer ofmaterial 4 placed over the lower part of the screen, as is shown inFIGS. 1 and 2. The aforesaid apertures may be free or open, that is theymay show the screen directly (FIG. 2), or into each of them there may beinserted a key 5 having its upper part 6 made of transparent material sothat the underlying screen may be visible, as is shown diagrammaticallyin FIG. 3.

From each aperture 3 there starts an optical fiber 7 (embedded in thematerial 4 covering the part of the screen intended for the keyboard)leading to a photodetector 8 (FIG. 4).

The electron beam of the tube scans one line of the screen 2 after theother in succession. In correspondence with each aperture the electronbeam is modulated in such manner as to produce on the screen analphanumeric symbol characteristic of the zone in which the symbol isgenerated. More particularly, each line of the screen is divided into somany points 9 the combination of which forms spatially, as has alreadybeen said, a character in correspondence with each aperture;

Let us assume that each line in correspondence with each aperture orzone is divided into 10 points and the complete zone is formed by sevenlines (FIG. 5). Also suppose, as is shown in FIG. 5, that the zonescorresponding to the keys are adjacent, (though this need not be thecase).

Three counters operate in synchronism with the scanning of the screen bythe electron beam, these being a line counter 10, a zone counter 11 anda counter 12 for points inside a zone (FIG. 6). The electron beam beginsto sweep the second part of the screen, that is the part which functionsas a keyboard. The deflection control unit 13 of the cathode ray tubestarts the counters, which therefore count in synchronism with thescanning of the second part of the screen by the electron beam. At thebeginning of the scan, the zone counter initiates the count, that is itcounts 1 as long as the beam remains in the first zone. The front of thesignal CZl supplied by the counter 11 on the count of the first zonecommands a character generator which, in this particular example, isformed by a 5 X 7 core matrix 16.

The matrix is controlled by a control unit 14 from which there emerge asmany leads as there are characters for the zones of the keyboard. Thewires are so linked with the cores of the matrix 16, so that, when thecommand arrives from the zone counter the unit 14 activates a certainprogrammed character wire, whereby all and only those cores which givespatially the form of the character itself are put into the I state.

It is assumed that the character l is assigned to the first zone, sothat with the rise of the signal CZl of the zone counter 11 there areenergized in the matrix those cores which form spatially the characterI. The core matrix moreover has another two inputs. The rows of thematrix are energized by the line counter 10. If the first one hundredscan lines of the screen are used for the visual display of the message,the command C101, that is the command supplied by the counter on thecount of the 101st line (first line of the second part of the screen),energizes the first row of the matrix, and so on in succession with thecommands C102-2-4-5-6 up to the command C107, which enables the seventhrow of the matrix.

When the scanning beam is on the line 101, the first row of the matrixis energized. During the interval of the first zone, the times from 4 to8 corresponding to the count from 4 to 8 of the points which is suppliedby the point counter 12 in a zone energize the five columns of thematrix in succession. The previously set cores are now reset insuccession each core being reset when there are coincident currents inthe row and column intersecting at the core. The outputs of the fivecolumns of the matrix are fed as OR function to a unit 15 which controlsthe grid of the cathode ray tube and hence the intensity of the beam. Inthis way, a point which corresponds to the sole point of the character 1in the first line will appear illuminated with a certain intensity inthe first zone. As the electron beam continues to scan the lines 101 to107, the characters corresponding to the respective zones and determinedby suitable prewiring of the core matrix 16 will appear. At the end ofthe scanning process, the characters will be visible with a reducedluminous intensity in the apertures corresponding to the keys and to theaforesaid zones. The phosphor of the screen, when bombarded by theelectron beam, emits by fluorescence and phosphorescence the lattergiving rise to persistence. Assume that the photodector 8 is selectiveas to frequency and reacts to the fluorescence only and assume,moreover, that the fluorescence at a point is sub stantiallyinstantaneous, the curves of two adjacent points being non-superimposed.As the electron beam scans the lines of the screen, it excites or notgiven points (unitary segments), as a result of which the light wavesare conveyed by the optical fiber corresponding to the zone of which thepoint contributing to the formation of the character forms part, to thephotodetector, which gives an output signal every time a point isexcited with a given intensity. If a finger is introduced into a givenaperture, or if a key is pushed into the aperture, the optical fiberwhich starts from this aperture no longer receives the instantaneouslight waves produced by the excitation of the points which form thecharacters and the photodetector no longer gives a signal.

As th e scanning of the zones continues, the inverter signal 1) from thephotodetector enters a group of AND gates 90, 91, 92, 93, 94, etc. equalin number to the number of zones or keys. Each AND gate has as inputsthe clock signal, an output signal from the zone counter 11 whichidentifies the zone, the inverted output D of the photodetector and theoutput (after a delay consistent with the response time of thephotodetector) of the core matrix. In this way, an AND gate gives anoutput when a point which forms the character in the corresponding zoneis covered, that is the light information is not received by thephotodetector. The AND gates 90, 91, 92, 93, 94, etc. are respectivelyconnected to counters 110,111, 112, 113, 114, etc., which have thefunction of counting the points of the character in the respective zonewhich are covered. Each counter is required to count not all the pointswhich form the corresponding character, but some, therefore giving amajority decision. Assume that a finger is placed in the first zone onthe left at the top and the character 1" is defined in this zone byutilizing nine points of the 5 X 7 matrix. If the finger is placedeffectively over all the nine points of the character, there will benine outputs from the AND gate 90 and, therefore, nine count pulses tothe first counter 110. The counter can however be set to confirm a 1 ifit has counted a lower number, for example seven. It is then sufficientfor the finger to cover any seven points of the character 1 in the firstzone in order that the counter may give the information that thecharacter 1 has been entered. Each counter can count in dependence uponthe type of character associated therewith.

The outputs A to E of the counters to 114 control a flip-flop FF. When acounter has completed its count, that is when a finger has covered agiven number of points of the character is a zone, a signal is generatedwhich sets the flip-flop FF. The output of the flip-flop FF enables anAND gate 200. The AND gate 200 has as input a signal 120, which is thelogical sum of the signals issuing from AND gates 13.0, 131, 132, 133,134, of which there are as many as there are zones in the keyboard. TheAND gate is supplied with the signal A leaving the counter 110 and thesignal G2] which is present throughout the time during which theelectron beam is in the first zone of the keyboard. The AND gate 131 issupplied with the signal B and the signal C22, and so on.

The output from the AND gate 200 is a signal X present only for the zoneperiod corresponding to the key pressed, which causes the outputs fromthe core matrix 16 to feed, via an AND gate 201, a unit 202 whichcontrols the grid 203 of the cathode ray tube 1 in such manner as togenerate an electron beam of greater intensity. In this way, the fingerhaving been removed from the aperture in the screen, the underlyingcharacter can be seen with a stronger luminous intensity, supplying theoperator with the information that the character has been entered.

The screen of the cathode ray tube has the first part 2 at the topadapted to give a visual display of a message. The message to bevisually displayed may be generated by the keyboard-operated enteringprocess carried out character by character or may be retrieved, by thekeyboard entering of a code, from a store present in a logic unit of thedevice. Referring to FIG. 7, the zone counter 11 feeds an encoding unit17 which can generate a code for each zone. The codes generated by theunit 17 are of two types; to the first type there belong codescorresponding to characters and symbols adapted to be visually displayedand to the second type there belong address codes of locations of a mainstore 19 in which messages are contained. Consequently, when a keycorresponding to an address code is operated on the keyboard, an ANDgate 18 is enabled by the signal X in such manner that in the main store19 there is addressed and read a certain location containing a givenmessage, which is transferred over the line 27 to a writing unit 21.

The unit 21 writes the codes coming from the wire 27 into a buffer store22, in particular of the delay line type, which is adapted to contain anentire block of characters equal to the entire capacity of the firstpart of the visual display screen of the tube 1.

When, on the other hand, a key corresponding to a character or symbolwhich is to be visually displayed directly is operated on the keyboard,the unit 17 feeds an AND gate 20 enabled by the signal X, transferringthe code representing the aforesaid character or symbol, which iswritten into the store 22 by the writing unit 21.

The store 22 is read by the unit 23'. Both the unit 21 and the unit 23receive from the channel 26' timing signals coming from the time baseunit 13 controlling the deflection of the cathode ray of the tube 1. Thecharacters issue from the store 22 in synchronism with the sweeping ofthe first part of the screen by the electron beam.

The codes leaving the unit 23 feed the control unit 14 of a charactergenerator, which is the 5 X 7 core matrix 16 already described. The corematrix is read by a count unit 24 which, in particular, may berepresented by the same counters 10, 11, 12, which are suitably adapted.

The embodiment of I the invention hereinbefore described provides formany variants. The main store 19 shown in FIG. 7 may be an integral partof a central processor to which the input-output device is connectedthrough the medium of atransmission control unit, Also inherent in theinvention is the complete modifiability of the keyboard by merereplacement of the plate indicated by the reference 4 in FIG. 1 byanother plate having an arrangement of the keys which differs inaccordance with the most diverse requirements. The modifiability canmoreover be given effect at character generation level, as a result ofwhich it is possible to obtain visual display of the most diverse typesof symbols. Instead of generating characters with a core matrix, thismay be effected with the use of a part of a store (for example a readonly store) for this function and the decision as to which type ofcharacters are to be visually displayed will be a programming task.Moreover for conducting the light from the key zones to thephotodetector, it is possible to employ, in the place of optical fibers,a uniform layer of transparent and photoconductive material placed overthe screen; this layer of material enables all the information ofpresence or absence of light on the screen to be transferred as itappears at the scanning rate given by the electron beam.

lclaim 1. A data input device for posting characters comprising acathode ray tube having a screen divided in a plurality of zones, andscreen scanning means for scanning said zones to cause the display of acharacter corresponding to the scanned zone in the same zone, whereinthe improvement comprises:

a photodetector for detecting the light generated by said zones,

a plurality of light conveying means for conveying the light generatedby said zones to said photodetector, and

a plurality of decoders each one associated with a corresponding one ofsaid zones and jointly activated by said photodetector and said scanningmeans to generate code signals corresponding to a zone of said pluralityof zones which is at least partially obscured.

2. A data input device according to claim 1, including a layer ofmaterial disposed over at leasta portion of said screen and havingapertures over each one of said zones, wherein said light conveyingmeans comprise a light guide extending from each of said zones to thephotodetector.

crease the intensity with which the electron beam of the cathode raytube scans the corresponding zone, thereby to illuminate thecorresponding symbol of said zone with greater intensity and confirminput of the character corresponding to said zone.

4. A data input device according to claim 2 wherein said light guidespass through said layer of material to said photodetector.

5. A data input device according to claim 4, wherein each of saidapertures is dimensioned to receive a finger or other body for obscuringthe zone corresponding to said aperture.

6. A datainput device according to claim 1, wherein the screen of thecathode ray tube is divided into a first part for the'display of symbolsand a second part comprising said zones, said device comprising meansresponsive to at least one of said code signals to display a messagecorresponding to said code signals on the first part of the screen.

7. A data input device according to claim 6, wherein said display meanscomprise a buffer store for storing in succession the code signalsprovided by said plurality of decoders as the second part of the screenis scanned, and a symbol generator coupled to said buffer store andresponsive to the code signals stored therein during scanning of thefirst part of said screen by said scanning means for displaying amessage made up of symbols corresponding to the codes of the codesignals on the first part of the screen.

8. A data input device comprising:

a cathode ray tube having a screen divided into a plurality of zones,each of said zones being associated with a corresponding character andindividually conditionable for posting said corresponding character,

displaying means for displaying said characters by exciting the zones ofthe screen according to the corresponding characters, and

display control means responsive to the conditioned zone for causingsaid displaying means to incrementally excite the conditioned zone,whereby the posted character is displayed by an incrementally increasedlight.

9. A data input device according to claim 8, wherein said displayingmeans comprise an electron beam generator and said display control meanscomprise decoding means for decoding the zone of the screen to beincrementally excited, and circuit means activated by said decodingmeans for causing said electron beam generator to generate an electronbeam of greater in-

1. A data input device for posting characters comprising a cathode raytube having a screen divided in a plurality of zones, and screenscanning means for scanning said zones to cause the display of acharacter corresponding to the scanned zone in the same zone, whereinthe improvement comprises: a photodetector for detecting the lightgenerated by said zones, a plurality of light conveying means forconveying the light generated by said zones to said photodetector, and aplurality of decoders each one associated with a corresponding one ofsaid zones and jointly activated by said photodetector and said scanningmeans to generate code signals corresponding to a zone of said pluralityof zones which is at least partially obscured.
 2. A data input deviceaccording to claim 1, including a layer of material disposed over atleast a portion of said screen and having apertures over each one ofsaid zones, wherein said light conveying means comprise a light guideextending from each of said zones to the photodetector.
 3. A data inputdevice according to claim 2, comprising further means responsive to saidcode signals to increase the intensity with which the electron beam ofthe cathode ray tube scans the corresponding zone, thereby to illuminatethe corresponding symbol of said zone with greater intensity and confirminput of the character corresponding to said zone.
 4. A data inputdevice according to claim 2 wherein said light guides pass through saidlayer of material to said photodetector.
 5. A data input deviceaccording to claim 4, wherein each of said apertures is dimensioned toreceive a finger or other body for obscuring the zone corresponding tosaid aperture.
 6. A data input device according to claim 1, wherein thescreen of the cathode ray tube is divided into a first part for thedisplay of symbols and a second part comprising said zones, said devicecomprising means responsive to at least one of said code signals todisplay a message corresponding to said code signals on the first partof the screen.
 7. A data input device according to claim 6, wherein saiddisplay means comprise a buffer store for storing in succession the codesignals provided by said plurality of decoders as the second part of thescreen is scanned, and a symbol generator coupled to said buffer storeand responsive to the code signals stored therein during scanning of thefirst part of said screen by said scanning means for displaying amessage made up of symbols corresponding to the codes of the codesignals on the first part of the screen.
 8. A data input devicecomprising: a cathode ray tube having a screen divided into a pluralityof zones, each of said zones being associated with a correspondingcharacter and individually conditionable for posting said correspondingcharacter, displaying means for displaying said characters by excitingthe zones of the screen according to the corresponding characters, anddisplay control means responsive to the conditioned zone for causingsaid displaying means to incrementally excite the conditioned zone,whereby the posted character is displayed by an incrementally increasedlight.
 9. A data input device according to claim 8, wherein saiddisplaying means comprise an electron beam generator and said displaycontrol means comprise decoding means for decoding the zone of thescreen to be incrementally excited, and circuit means activated by saiddecoding means for causing said electron beam generator to generate anelectron beam of greater intensity in correspondence with said decodedzone.
 10. A data input device according to claim 9, wherein saiddecoding means comprise a photodetector responsive to the lightgenerated by each zone and generating a signal when a zone is at leastpartially obscured, scanning means for cyclically scanning said zones,and gate means associated with each of said plurality of zones andresponsive to said scanning means and to the signal generated by saidphotodetector to activate said circuit means.